1. Field of the Invention
The present invention relates to improvements of an automatic document transfer device by which a document is fed, and transferred and carried out, and further relates to an automatic document transfer device in which means for transmitting a drive force of a document feeding section to a document transferring section has been improved, in an image forming equipment equipped with a document feeding section and a document transferring section, both of which can be engaged and disengaged by opening and closing the document pusher plate.
2. Description of the Prior Art
As one of automatic document transfer devices in the image forming equipment, such a type as consists of a document feeding section having document feeding means therein and installed at the body side of the image forming equipment, and a document pusher plate which is pivotally mounted on the document table of the image forming equipment body so that it can be freely opened and closed, installed in the vicinity of the document feeding section and is provided with transferring means by which a document is transferred to the position of exposure of the document table of the image forming equipment body and is taken out after exposure, is already available.
When automatically transferring a document in such an automatic document transfer device as shown in the above, a document is led from a document tray mounted at the document feeding section to the transferring means through the document feeding means with the document pusher plate closed on the document table on the image forming equipment body.
Furthermore, the document is led to the position of exposure on the document table, and after being exposed it is taken out by the transferring means onto a document receiving section on which the exposed documents are piled.
At this time, conventionally, the document feeding means and the transferring means have been separately driven by an independent source of power, respectively.
An automatic document transfer device by which both the document feeding means has appeared recently and the transferring means which are divided each other and installed adjacent to each other can be driven by a single source of power. Such an automatic document transfer device has been disclosed for instance in the Japanese Patent Application No. Sho-63-61333. However, in such an automatic document transfer device, a linkage member which can be connected and disconnected is needed, respectively, for both the document feeding means and the transferring means because they are separately mounted.
In such an automatic document transfer device 1a as mentioned in the above, as shown in FIG. 7, the document pusher plate 19 is opened up to the position shown with a two-dot dashed line (19') and is shifted down to the position shown with a solid line (19) under the closed condition thereof. In accompanying therewith, the second linkage gear 16 attached to the document pusher plate 19 is shifted down to the position shown with the solid line (16) from the position shown with the two-dot dashed line (16').
On the other hand, the guide plate 25a is pivotally mounted at the side plate 22a fixed at the document feeding portion 10a by way of the rotary axis 24. And the guide plate 25a is always turned and energy-charged in the clockwise direction on the illustration by means of a spring 27. The first linkage gear 8 provided on the guide plate 25a is so composed that the gear 8 can be engaged with the second linkage gear 16 which has been shifted down to the closed position shown with the solid line.
Thus, as the above automatic document transfer operation becomes available upon a completion of engagement between the first linkage gear 8 and the second linkage gear 16, thereby causing a source of power (not illustrated), which is built in the document feeding means 9a of the document feeding section 10a, to stand by.
As mentioned in the above, in the conventional automatic document transfer device 1a, a simple construction is adopted, and the document feeding means 9a and the transferring means 18 are so linked with each other that they can be engaged and disengaged, thereby causing respective means to be driven by a single source of power. Namely, it is convenient in this meaning.
Hereupon, in such an automatic document transfer device 1a mentioned above, as shown in FIG. 7, when the force of a spring 27 is weak, teeth skipping of the above linkage gears may be apt to occur, and especially as it is possible for the first linkage gear 8, which can swing, to escape in the opposite direction of the direction of rotation shown by an arrow 26 when the first linkage gear 8 rotates in the direction of an arrow 28, the teeth skipping is more apt to occur.
For this reason, as normal rotation is not transmitted to the second linkage gear 16, some difference may occur in the transferring distance of the document, thereby causing some hindrance to occur in the processing such as exposure for image forming and noises to be resulted therefrom.
Or in the case that the force of the spring 27 is strong, the above linkage gears are forcedly brought into contact therewith mutually by the energy charged by the spring 27 to eliminate a moderate play between respective teeth, thereby causing large friction to occur when the linkage gears rotate, the source of power to be loaded, and respective teeth thereof to be apt to be worn.
In the case that the force of the spring 27 is stil further strong, the document pusher plate 19 at which the second linkage gear 16 is pivotally mounted by the first linkage gear 8 energy-charged by the spring 27 can not keep the prescribed position shown with the solid line (19) but may be floated or raised up.
For this reason, a discrepancy may occur in the positional relationship, which is to be in accord in the case that the force of a spring 27 is adequate, between the document feeding port (not illustrated) open toward the transferring means 18 and the receiving portion (not illustrated) of the transferring means 18 in which a document is received from the document feeding port. Therefore, there is a problem that a document jam is apt to occur at the document feeding portion 10a and the document feeding ability may become worse.